Collaboration comments from Alan, Darien, Dmitri, Elemer ... fileJean-Francois, Jerry, John, Marc and Tom All supportive of publication Mostly style and presentation. Collaboration

Collaboration Collaboration Comments on Comments on "Search for "Search for Resonant Resonant Slepton Slepton Production"Production"

Christian Autermann Christian Autermann All D0 meetingAll D0 meeting

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Search for Resonant Slepton Production

C. A., Thomas Hebbeker, Arnd Meyer

Collaboration comments from Alan, Darien, Dmitri, Elemer, Greg,Jean-Francois, Jerry, John, Marc and TomAll supportive of publicationMostly style and presentation



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Analysis Summary I: Analysis Summary I: SleptonSlepton Production Production

→ 2 jets and 0, 1 or 2 µ

Require 2 muons to control the QCD multijet background→ Possible to reconstruct the

neutralino and the slepton mass→ But only ~25% branching ratio

(ν)~

(ν)~

(ν )µ

(ν )µ



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Analysis Summary II: Signal ChannelsAnalysis Summary II: Signal Channels

Final state: 2-muon & 2-jet Three dominant signal channels:

µχµ 01

~~→ µχµ 02

~~→ µχνµ±→ 1

~~

1. 2. 3.

→ Analyze each channel separately → Give limit on σ × BR for each channel,

depends only on masses, not models!



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mass [GeV]10χ∼

0 50 100 150 200 250

mas

s [G

eV]

µ∼

50

100

150

200

250

300

350

400

450

500

) [p

b]

µ 10 χ∼

→µ∼ B

R(

×) µ∼→p

(pσL

imit

2

4

6

8

10

12

14

16

18

LEPGenerated points

D0 RunII preliminary

µχµ 01

~~ →

mass [GeV]10χ∼

0 50 100 150 200 250 300 350

mas

s [G

eV]

l~

100

200

300

400

500

600

LEP

Not allowed region in mSUGRA

Generated points

|=-1µ/|µ)=5, βtan(

0.02

0.04

0.06

0.08

0.1

0.12

0.14

0.16

0.18

0.2

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1’λ

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1’λD0 RunII

mass [GeV]1±χ∼, 2

0χ∼

0 100 200 300 400 500 600 700

Analysis Summary III: Results

Cross section limit Interpretation within mSUGRA

Plots in the PRL paper are black&white for better readability



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PreselectionPreselection “control plots”“control plots”C: Please show the SM uncertainty in the figuresA: dashed line

C: multiply signal by someamount

A: now factor of 5

C: What are the mSUGRAparameters for the signal?

A: The slepton mass is 260 GeV(caption), other parametersare not important (here).

(Caption: Reconstructed slepton mass)

C: change “slepton” to “smuon” mass

A: It’s either the reconstrctedsmuon or sneutrino mass, depending on signal channel.



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Style and Physics commentsStyle and Physics commentsC: Please change “D0” to “DØ” everywhere in the paperA: Style guidelines suggest to use “D0” to enable internet

search engines to find the D0 publications easier

C: Are the errors between Signal and SM expectation taken as 100% correlated? Why? E.g. k-factors should be independent.

A: The statistical errors of Signal and SM are uncorrelated.The systematical errors are assumed to be 100% correlated, to beconservative.The signal k-factor does only include NLO QCD corrections and noSUSY-QCD corrections (which are negligible for A0=0) and is therefore very similar to NLO corrections for “qq → W” or “qq → Z”.

C: Why are you using NLO PDF uncertainties with the LO Susygen generator ?A: We correct the LO Susygen cross section with NLO calculations using

CTEQ6.1M. The PDF uncertainties are extracted from the CTEQ6.1Merror functions



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Physics CommentsPhysics CommentsC: Why is the statistical SM uncertainty not the square-root of the

SM expectation ?A: Because the Monte Carlo luminosity is higher then the data’s.

The SM is scaled, so that the statistical error is reduced.

C: What is the kinematic limit at the Tevatron for the slepton mass?How far can the cross section limit plot be extented?

A: The cross section limit does not depend on the signal cross section.In principle a cross section limit of ~2pbcan be given for a slepton mass of 1.96 TeV(if we had generated signal at this point).

It just would not make a lot of sense to show a cross section limit for sleptonmasses above 500 GeV, because the potential signal would have a much smaller cross section.



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Physics CommentsPhysics CommentsC: The explanation of the QCD extraction from the data is too terseA: Reduced it to the essential method:

C: The final selection procedure is too short. Extent it! (50% of people)The final selection procedure is too elaborate. Shorten it! (50% of people)

A: The current paragraph is a compromise. The method is described, but no further details are given.

C: Why is the Luminosity error of the SM expectation only 5.5% and not 6.5%,like for the signal?

A: The QCD sample is scaled to the data and has no lumi-error, but a larger uncertainty is considered separately. Since the QCD contribution is approx.15% in this selection, the lumi uncertainty is 6.5% * 85% = 5.5%.

“Background from multi-jet QCD events was extracted from data using loose muon isolation requirements. At least one isolation criterion with respect to other energy depositions in the calorimeter or to other tracks must not be tight for at least one muon to separate QCD and the data sample.”



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How Good Is The Result?How Good Is The Result?C: How much better is the analysis compared to Run I?A: Run I excluded e.g. a smuon mass of 280 GeV

for λ’211=0.09 and m(χ10)=200 GeV

Now a smuon mass up to 358 GeV is excluded,

for λ’211=0.09 and independent of other masses, e.g. m(χ10)

→ Added this to the conclusion of the paper

A: An other example: (for m(l) = 263 GeV and m(χ) = 100 GeV)Run I set a limit λ’211≤ 0.09The limit is now λ’211≤ 0.028Since σ ∝ (λ’211)2 an improvement of 1 : 10



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Limit Contour Limit Contour Plot(sPlot(s))

C: Neat plotsA: ;-)

C: Labels hardly visibleA: Optimized color and

increased size

C: Include LuminosityA: done.

C: Remove 2nd x-axis (whichshowed the χ2

0, χ±1 masses)

A: done.



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ConclusionConclusion

• Presented search for resonant slepton production

• Analysis Note and PRL draft are available from the EB032 webpage

• All questions and answers can be found on the EBpages

• Thanks to all who send comments!

• Many thanks to the entire EB32 and especially tothe chairs Pierre Petroff and later Marc Besançon!



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Authentic scientific paper or gibberish?Authentic scientific paper or gibberish?http://montana.informatics.indiana.edu/cgi-bin/fsi/fsi.cgi

Gibberish paper generator:http://pdos.csail.mit.edu/scigen/

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Collaboration comments from Alan, Darien, Dmitri, Elemer ... fileJean-Francois, Jerry, John, Marc and Tom All supportive of publication Mostly style and presentation. Collaboration